System originally designed to handle a variety of primary (migration) data

• System originally designed to handle a variety of primary (migration) data

• Metadata is key as it describes the primary data held in the database. The system relies on this metadata to recognise the range of primary data stored

• The system has very few ‘hardcoded’ assumptions about the data – it is all looked up whenever a data page on the user’s browser is produced

• Data need only have a single origin and destination identifier, with a set of fields (generally a set of counts disaggregating the flow)